Arch Linux

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Installation

Download an ISO image, verify its signature and its checksum:

$ sha1sum -c archlinux-2015.06.01-dual.iso.sha1
archlinux-2015.06.01-dual.iso: OK

$ gpg --recv-keys 9741E8AC
$ gpg --verify archlinux-2015.06.01-dual.iso{.sig,}

Booting the image will not enter an installation routine but will drop to a shell. Set a (root) password and enable sshd:

passwd
systemctl start sshd.service

If necessary, add a default route for internet access too:

ip route add default via 10.0.0.1

Add DNS information:

$ grep '^[a-z]' /etc/resolv.conf
search local
nameserver 10.0.0.2

Now we should be able to login via SSH and continue with the installation. See the Installation guide for further steps.

Partitioning

If we decide for a GPT partitioning scheme[1]:

$ lsblk 
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0     4G  0 disk 
sr0     11:0    1   734M  0 rom  /run/archiso/bootmnt
loop0    7:0    0 317.8M  1 loop /run/archiso/sfs/airootfs

Note: since version 2.25, cfdisk also supports GPT. Let's use gdisk anyway for now:

$ gdisk /dev/sda
Command (? for help): o                                                     # create a new empty GUID partition table (GPT)
Command (? for help): n                                                     # add a new partition
Partition number (1-128, default 1): 
First sector (34-8388574, default = 2048) or {+-}size{KMGTP}: 
Last sector (2048-8388574, default = 8388574) or {+-}size{KMGTP}: +1M       # We need a 1 MB "BIOS boot partition" for GPT
Hex code or GUID (L to show codes, Enter = 8300): ef02
Changed type of partition to 'BIOS boot partition'

Command (? for help): n
Partition number (2-128, default 2):
First sector (34-8388574, default = 4096) or {+-}size{KMGTP}:
Last sector (4096-8388574, default = 8388574) or {+-}size{KMGTP}: -128M     # Use the the remaining disk space, minus 128 MB
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 
Changed type of partition to 'Linux filesystem'

Command (? for help): n
Partition number (3-128, default 3): 
First sector (34-8388574, default = 8126464) or {+-}size{KMGTP}: 
Last sector (8126464-8388574, default = 8388574) or {+-}size{KMGTP}:        # Use the remaining disk space
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 8200
Changed type of partition to 'Linux swap'

Command (? for help): p
Disk /dev/sda: 8388608 sectors, 4.0 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 7EE317A0-6C4F-4A93-B0E7-D03BFC83F283
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 8388574
Partitions will be aligned on 2048-sector boundaries
Total free space is 2047 sectors (1023.5 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
  1            2048            4095   1024.0 KiB  EF02  BIOS boot partition
  2            4096         8126430   3.9 GiB     8300  Linux filesystem
  3         8126464         8388574   128.0 MiB   8200  Linux swap


Command (? for help): w                                                     # write table to disk and exit

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING PARTITIONS!!

Do you want to proceed? (Y/N): Y
OK; writing new GUID partition table (GPT) to /dev/sda.
The operation has completed successfully.

Note: the cgdisk routine would have been easier ;-)

File systems

Create file systems:

mkfs.jfs /dev/sda2                                           # See these notes for supported file systems
mkswap /dev/sda3

$ blkid -s TYPE
/dev/sda2: TYPE="jfs"
/dev/sda3: TYPE="swap"
/dev/sr0: TYPE="iso9660"
/dev/loop0: TYPE="squashfs"

Enable swap, mount file systems:

mount -t jfs /dev/sda2 /mnt
swapon /dev/sda3

Software

Adjust mirror list:

cp /etc/pacman.d/mirrorlist mirrorlist.orig
grep -A1 United\ States mirrorlist.orig | sed 's/^--//' > /etc/pacman.d/mirrorlist            # Adjust as needed!

Install the base group:

$ pacstrap /mnt base
==> Creating install root at /mnt
==> Installing packages to /mnt
[...]

Generate an fstab:

genfstab -p /mnt >> /mnt/etc/fstab

chroot into the new installation:

arch-chroot /mnt

Configure more system settings:

echo arch0 > /etc/hostname
ln -sf /usr/share/zoneinfo/PST8PDT /etc/localtime

Install locales:

$ grep -v ^\# /etc/locale.gen
en_US.UTF-8 UTF-8  

$ locale-gen
Generating locales...
  en_US.UTF-8... done

$ echo LANG=en_US.UTF-8 > /etc/locale.conf

Bootloader

Configure & create initrd:

$ grep ^[A-Z] /etc/mkinitcpio.conf
MODULES="jfs"
BINARIES=""
FILES=""
HOOKS="base udev autodetect modconf block filesystems keyboard fsck"

$ mkinitcpio -p linux
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'default'
 -> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux.img
[...]

Install the GRUB bootloader:

$ pacman -S grub
[...]
$ grub-install --recheck /dev/sda
Installing for i386-pc platform.
Installation finished. No error reported.

$ grub-mkconfig -o /boot/grub/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-linux
Found initrd image: /boot/initramfs-linux.img
Found fallback initramfs image: /boot/initramfs-linux-fallback.img
done

Network

Create configuration file for netctl

$ cd /etc/netctl/
$ cp examples/ethernet-static enp0s3                             # Adjust the NIC name!

$ cat enp0s3 
Interface=enp0s3
Connection=ethernet
IP=static
Address=('10.0.0.32/24')
Gateway='10.0.0.1'
DNS=('10.0.0.2')

$ netctl start enp0s3                                            # Running in chroot, ignoring request.
$ netctl enable enp0s3

Install OpenSSH:

pacman -S openssh
systemctl enable sshd.service
systemctl start sshd.service                                     # Running in chroot, ignoring request.

Enable pam_cracklib:

$ grep ^p /etc/pam.d/passwd 
password        required        pam_cracklib.so difok=2 minlen=8 dcredit=2 ocredit=2 retry=3
password        required        pam_unix.so sha512 shadow use_authtok

Set a password:

$ passwd 
Enter new UNIX password: 
Retype new UNIX password: 
passwd: password updated successfully

If all went well, the machine can be rebooted and should be installed now.

Packages

Install missing packages:

pacman -S --needed  arpwatch atop autossh bash-completion bc binutils checksec cronie cryptsetup dosfstools ecryptfs-utils git haveged hdparm iftop iotop iperf3 lsof make mlocate moreutils nfs-utils nftables nrpe openbsd-netcat p7zip pbzip2 pigz pv rsnapshot rsync screen smartmontools ssmtp strace sudo syslog-ng sysstat systemd-swap tcpdump unrar unzip vim vnstat w3m zstd


Enable various daemons as needed:

systemctl enable cronie.service haveged.service
systemctl start  cronie.service haveged.service

Postinst

rc.local

Since Arch Linux is using systemd, let's create an rc.local equivalent:

$ cat /etc/systemd/system/rc-local.service
[Unit]
Description=/etc/rc.local Compatibility

[Service]
Type=idle
ExecStart=/etc/rc.local start
StandardOutput=journal+console

[Install]
WantedBy=multi-user.target

$ sudo systemctl enable rc-local.service

The file /etc/rc.local needs to be executable too. Example:

$ sudo chmod 0700 /etc/rc.local
$ cat /etc/rc.local
#!/bin/sh
logger "$0: test"

$ sudo systemctl start rc-local.service
$ sudo journalctl -n 1
-- Logs begin at Wed 2015-10-07 11:51:19 PDT, end at Wed 2015-10-07 12:39:13 PDT. --
Oct 07 12:39:06 arch0 root[278]: /etc/rc.local: test

updatedb

Install mlocate:

sudo pacman -S --needed mlocate

Enable the periodic updatedb generation:

$ cat /etc/cron.daily/updatedb
#!/bin/sh
/usr/bin/sudo -u nobody /usr/bin/updatedb

Adjust the database directory, so updatedb doesn't need to be run as root:

chown -c nobody:locate /var/lib/mlocate/
chmod -c 2750 /var/lib/mlocate/

Update

Arch Linux follows a rolling release model[2][3] and while an Arch system can be updated, there are no releases and the term upgrade may not apply.

Download fresh package databases from the server

pacman --sync --refresh --refresh                        # Short: pacman -Syy

Update installed packages:

pacman --sync --refresh --sysupgrade                     # Short: pacman -Syu

Links

References